From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-2?Q?Andr=E9s Gri=F1=F3 Brandt?= Date: Thu, 07 Mar 2002 07:37:04 +0000 Subject: [LARTC] Src IP for outgoing packet with multiple defaults routes Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: lartc@vger.kernel.org Hi: Abstract: Linux connected to two different ISP. Outgoing packets seems to p= eek randomly it's source IP address, without regards to the router choosen. Test bed: 1. Linux Red Hat 7.2 (fw1) with kernel 2.4.7-10, no patches, all netfilter = and adv. routing options on. 2. One "internet" ethernet card that connect to a switch. The switch connec= t the two routers also. 3. Linux have two IP: 200.72.44.226 and 200.27.214.226. 4. ip route list show: 200.72.44.224/27 dev eth0 scope link 200.27.214.224/29 dev eth0 proto kernel scope link src 200.27.214.226 default equalize=20 nexthop via 200.27.214.225 dev eth0 weight 1 nexthop via 200.72.44.225 dev eth0 weight 3 6. No MASQ, no SNAT, no DNAT for packets locally generated. 6. Ethercap running in eth0. 5. Another Linux (ws1) also running ethercap over the wire between router 2= 00.27.214.225 and the switch (via a hub). This machine have address 200.27.= 214.227. What I see, after running ethercap at the same time (and for the same perio= d) on both machines: 1. Ethercap on fw1 capture ~4.500 packets, on sw1 capture ~1.900 packets. 2. On sw1 ethercap show me only packets routed thru router 200.27.214.225. = I check the destination mac address, and it definitly router 200.27.214.225. 3. But on sw1, I see outgoing packets having both source IP 200.27.214.226 = and 200.72.44.226. This is wrong. Packets with source IP 200.72.44.226 must not reach router 2= 00.27.214.226. AFIK, an outgoing packet must have a source address in the s= ame subnet that the router being used. Ideas? Andr=E9s Gri=F1=F3 Brandt Santiago, Chile http://galeria.porsiempre.cl [Fotos de viajes, familia, club, etc.] http://club.porsiempre.cl [Sitio del Club Buceo Aventura] http://buceo.porsiempre.cl [P=E1gina Personal] ------------------------------ http://jawmail.sourceforge.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/